All aircraft employ control surfaces on the wings, tail or fuselage. These control surfaces take the form of ailerons, leading edge flaps, rudders, elevators and others. These control surfaces are pivoted to provide a control moment. Gaps form between the control surface and the aircraft, when the control surface is pivoted. These gaps allow aerodynamic spillage reducing the effectiveness of the control surface. Present aircraft use preformed composite blade seals, that are placed over the hingeline edge of the control surface to reduce the aerodynamic spillage. The blade seals are preformed to have sufficient preload to keep against the control surfaces during flight operations. As the control surface is pivoted against the composite blade seal, the seal is bent to conform to the control surface. Unfortunately, present blade seals can be very stiff requiring significant actuation force by the control surface to bend. This problem is particularly acute where the moldline of the aircraft curves in the area of the hingeline.
Thus there exists a need for a blade seal that does not require a large actuation force to bend.